The term Reichstag (in English: Imperial Diet) is a composition of German Reich (Empire) and tag (which does not mean "day" here, but is a derivate of the verb tagen, which means assembling for debate). The Latin term, a direct translation, was curia imperialis. (Still today, the parliaments on the various federal levels in Germany are called Bundestag, Landtag etc.)
The Reichstag in the Holy Roman Empire
While the Holy Roman Empire lasted (formally until 1806), the Reichstag never was a parliament in today's sense; instead, it was the assembly of the various leaders that Empire was comprised of. More precisely, it was the convention of the Reichsstände (imperial states), those legal entities that, according to Feudal law, had no authority above them besides the Emperor himself (see Holy Roman Empire for details).
The precise role and function changed over the centuries, as did the Empire itself, while the states gained more and more control at the expense of the imperial power. Initially, there was neither a fixed time nor location for the Reichstag. It started as a convention of the dukes of the old Germanic tribes that formed the Frankish kingdom when important decisions had to be made, probably based on the old Germanic law that each leader relied on the support of his leading men. For example, already under Charlemagne, the Reichstag in Aachen in 802/803 officially declared the laws of the Saxons and other tribes. The Reichstag of 919 in Fritzlar elected the first Saxon prince, Henry the Fowler, king of the Germans (Henry I), thus overcoming the longstanding rivalry between Franks and Saxons and laying the foundation for the German Empire. In 1158, the Reichstag in Roncaglia finalized four laws that would significantly alter the (never formally written) constitution of the Empire, marking the beginning of the steady decline of the central power in favor of the local dukes. In 1356, the Golden Bull cemented the concept of Landesherrschaft, the largely independent rule of the dukes over their respective territories.
However, until the late 15th century, the Reichstag was not actually formalized as an institution. Instead, the dukes would irregularly convene at the court of the king; these assemblies were usually referred to as Hoftage (from German Hof = "court"). Only beginning in 1489 was the Reichstag called as such, formally divided into several collegia, initially being the Kurfürsten (Electors) and other dukes. Later, those cities that were reichsunmittelbar, that is, oligarchic republics independent of a local ruler, formally only responsible to the Emperor himself, managed to be accepted as a third party.
Several attempts to "reform" the Empire to end its slow disintegration, starting with the Reichstag in 1495, did not have much effect. In contrast, this process was quite concluded with 1648's Peace of Westphalia, which formally bound the Emperor to all decisions made by the Reichstag, in effect depriving him of his few remaining powers. From then to its end in 1806, the Reich was merely a loose collection of largely independent states.
Probably most well known are the Reichstage in Worms of 1495, where the Imperial Reform was concluded, another in 1521, where Martin Luther was banned (see Edict of Worms), and several in Nuremberg; see Diet of Worms and Diet of Nuremberg for details.
Only with the induction of the Immerwährender Reichstag in 1663 did the Reichstag permanently convene in a fixed location, the city of Regensburg.
For a list of members of the Reichstag as of 1792, near the end of the Empire, refer to List of Reichstag participants (1792).
The Reichstag as the German Parliament
The opening of the German parliament in 1894
After the implosion of the Empire in 1806, the term was subsequently used for the Parliament of the 1849 Frankfurt constitution draft that never came into effect, the Parliament of the Norddeutscher Bund from 1867--1871 and finally that of the 1871 German Empire. In all three cases, it was a parliament elected by the people, albeit with varying degrees of power (the 1871 Empire was no democracy in any real sense).
In the 1919 Weimar Republic, the Reichskanzler (Chancellor, head of government) was elected by and responsible to the Reichstag, which was directly elected by the people. From 1930 on, however, the Reichstag was practically circumvented with the use of the extensive powers that the constitution granted to the President. After Adolf Hitler was appointed Reichskanzler on January 30, 1933 the process of Gleichschaltung commenced with the Reichstag Fire Decree and the Enabling Act (Ermächtigungsgesetz), in which the Reichstag formally dispensed of its legislative powers. From then on it only functioned as a body of acclamation for the actions of the dictatorship. Even with this purpose, it had its last session in 1942.
The Reichstag building in Berlin was constructed as the seat of the Reichstag in the German Empire and, after a major reconstruction, has been the seat of today's German parliament, the Bundestag, since 1999.
Collection of Imperial Records
After the 1871 formation of the German Empire the Historical Commission of the Bavarian Academy of Sciences started to collect imperial records (Reichsakten) and imperial diet records (Reichstagsakten). In 1893 the commission published the first volume. At present the years 1524 - 1527 and years up to 1544 are being collected and researched. A volume dealing with the 1532 Reichstag in Regensburg including the peace negotiations with the Protestants in Schweinfurt and Nuremberg, by Dr. Rosemarie Aulinger of Vienna was published in 1992.
The enormous amount of records in numerous archives and libraries in Germany, Austria, Switzerland, France, Italy, Spain, Denmark, England and Poland needs to be made available, gathered and worked through.
A list on the internet titled Das Reich um 1500, Dynastien - Fürstentümer - Residenzen, Höfe und Residenzen im spätmittelalterlichen Reich, "The Empire around 1500, Dynasties - Dukedoms - Residences, Ducal Courts and Residences in the Empire of the late middle ages" identifies the thousands of different localities. It gives an indication of the monumental task of locating and working on these official records, spread over large areas by the many different rulers, who all had the choice of their preferred seat of residence and government.